Pain durning sex

So whenever I have sex with my SO there's this area directly inside of me that will always get irritated and hurt when he first goes in. As we get going the pain goes away in that spot but then I can feel it again after we're done, and when I pee afterwards. This occurs no matter how much foreplay we do, lube used, or even if I orgasm prior to sex through oral. Does this happen to anyone else? Know what this is? Thank you for any answers or thoughts.